Austro-Portuguese Alliance

The Austro-Portuguese Alliance began on 11 May 1836 after the Kingdom of Portugal and the Austrian Empire agreed on an alliance in Vienna, Austria.

History
In 1836, Queen Maria II of Portugal sent envoy Joaquin da Sao Martin to Vienna in the Austrian Empire to negotiate an alliance with Emperor Ferdinand I of Austria, hoping for an ally in Central Europe. Portugal and Austria had been mutual friends during the Napoleonic Wars, as they both fought against France, but they were never officially allied (Portugal was then an ally of the United Kingdom, Austria's ally). Sao Martin took a ship to Trieste in Austrian Italy and traveled overland to Vienna, Austria, where he met with Austrian dignitary Klaus von Sturpnagel. Sturpnagel and Sao Martin discussed the possibility of an alliance in the event of an Austro-French War or a French intervention in the Liberal Wars in Portugal, and the two agreed to an alliance. On 11 May 1836, the Treaty of Vienna was signed, confirming the alliance.